Cold air blowing from passenger side vents and windshield defroster regardless of control or temp settings. Driver side temp adjustments work properly, but passenger side and windshield defroster controls do not provide any heat. Windshield does not defrost, as temp mix is not functioning for passenger vents or for windshield defroster. Problem has not been resolved.

- Woodbridge, VA, USA

I own a 2002 Jeep Grand Cherokee overland with 44,500 miles. The events leading up to the failure of the ventilation system were (1) rapid fogging of front windshield, (2) fogging of front passenger windows, (3) failure of passenger heat while still maintaining driver heat function, and (4) only cold air release on passenger side of Jeep. Consequently, (1) the windshield and front windows do not defog, and (2) no heat whatsoever comes from the passenger side floor and dashboard ventilation system. In addition to the fogging there is a leak of antifreeze, hazardous material, coming into the vehicle driver and passenger areas, due to defective heater core. To correct this problem, a "blend air door" is necessary and a new heater core at a cost of approximately $1,700 inclusive of 7 hours of labor. According to the certified service department at the local Jeep dealer and online forums, this has become a very common problem for 2000-2004 Jeep Grand Cherokee limiteds/overlands with dual zone ventilation systems.

- Lawrence, MA, USA

Defroster / defogger failed to produce warm air resulting in restricted visibility. Dealer had to replace the "blend doors" within the defrost / heater system. Cost of repairs was $1100+. visibility: Defroster/defogger system:windshield:blower.

- Hollidaysburg, PA, USA

Blend door mechanism broke numerous times, blower motor resistor burnt up twice.

- Roseburg, OR, USA

Heater/air conditioner ventilation system not functioning properly. Just stopped working. Would not direct heat/air to all vents. Was not covered by extended warranty, even though they knew there was a defect in the equipment. $1200+ to fix with a couple $10 parts! the whole dash has to come off.

- Sterling, IL, USA

Climate control blend door failure - fogged up front window and nearly caused an accident.

- River Forest, IL, USA

Dual climate control is broken. Cold air on one side & hot air on the other side.

- Vilas, NC, USA

I can't believe after reading on the internet and reading the complaints on this site about this problem that nothing has been done! I own a 2002 Jeep grand cherokeellimited with dual heat zone. I recently lost heat on the passenger side. Now you ask how is this a safety issue? well when you have it on defrost you have heat on the driver's side and ice cold air blowing on the passenger side. (remember that when you have the defroster on the A/C pump circulates which causes very cold air to blow) now only part of your windshield is clearing up. I live in central pa where the weather is always changing. Especially in the fall and spring. This temperature change can cause the windshield to fog up rather quickly especially when it's damp and there are warm bodies in the car. This can occur when your driving down the road at any time. I work for Napa auto parts and travel in 3 states. I'm a former vehicle technician and know a lot of repair shops. I was blown away at how many of theses repair shop knew exactly what the problem was and said that this is very common. They also stated that it is very time consuming and very costly to repair. Most dealership stock the parts to repair this. This alone should throw up a red flag! the blend doors were designed very cheaply and we the consumer have to pay for it. Anyone can see the hazard here the question is, will somebody do something before there is a death? ( there may have already been some, but nobody will ever know if the person is dead!). now you know why this should be a recall. I can tell you that not many people are aware of this website. You would have a lot more complaints on this issue if they did.

- Altoona, PA, USA

Visibility heating and cooling. Passenger side air wont heat. Drivers side works fine on dual climate control overland. Passenger side will not. When I phone my local dealer here in yankton sd, the service rep actually completed my sentence when I was describing the problem. He indicates this is a repeating ongoing problem with the Grand Cherokee. He even described the impaired vision as a result of the very well known malfunction. He told my wife and I that unless there is a severe chance of personal injury Jeep will not step up to the plate and take responsibility for this poor design flaw. Also he indicated it may cost as much as $1500 to fix. He suggested I stuff plastic bags into the heat duct to stop the flow of cold air until I get it repaired. He commented that poor visibility will continue if not worsen by doing so. Plain and simple, Jeep needs to take accountability for their design flaw. The know the problem is theirs but continue to take advantage of their customers for their own doing. If I wanted this kind of treatment, I would of purchased a GM. The Tacoma, great performer and service people who don't take you for an idiot.

- Crofton, NE, USA

Windows fog up so bad I can't see on right side of car. Cold air blows out on passenger side even as the temp control is set on hi position. Ran diag. On HVAC and error code 52 = ai (recirc) door travel range too large & 56 = right temperature door travel too large.

- Quincy, IL, USA

Heat failed on passenger side.

- Plymouth, OH, USA

I own a 2002 Jeep Grand Cherokee overland with 60,000 miles. The events leading up to the failure of the ventilation system were (1) rapid fogging of front windshield, (2) fogging of front passenger windows, (3) failure of passenger heat and driver heat function, and (4) only cold air release on both sides of Jeep. Consequently, (1) the windshield and front windows do not defog, and (2) no heat whatsoever comes from the passenger side floor and dashboard ventilation system. To correct this problem, a "blend air door" is necessary at a cost of approximately $1,200 inclusive of 7 hours of labor. According to the certified service department at the local Jeep dealer and online forums, this has become a very common problem for 2000-2004 Jeep Grand Cherokee limiteds with duel zone ventilation systems.

- Vancouver, WA, USA

Events leading up to failure: Normal usage of vehicle cabin comfort and safety controls (air conditioning/demister) systems. Failure: Cabin air conditioning system now does not regulate temperature. The system cannot be made to use hot or cold air on demand. In investigating this failure, it has come to my attention that 99% of all other owners of this vehicle report experiencing a failure of the 'temperature blend control doors' within the 'A/C blend assembly'. consequences: The vehicle demister is unable to clear the front windshield of mist/fogging (effectively, depending on outside temperature). Corrections: No corrections have been performed due to cost prohibitive expense to do so. The local dealerships quote a price of around $1800 to repair the failure, while obtaining parts and performing self-repair will cost upwards of $300 plus time spent.

- Newport News, VA, USA

I own a 2002 Jeep Grand Cherokee limited. Late winter, when I needed it the most, my heat began not working only on the driver's side of the vehicle. The passenger side had plenty of heat though. I took it to the dealer and after a $1100 repair bill to repair the blend doors inside the ac system (mostly labor), it was repaired. Today, again, I have no heat and now no ac too. A diagnosis now says that I have a code for "travel too large"-this is the code for the blend doors again. After an internet search, I see that there are many, many others like me who are having the same issue. This is a safety concern as in the winter, there is no way to clear the windshield with the cold air. Dailmer Chrysler needs to do the right thing here and stop profiting from their own defects. This should be a recall to repair all affected vehicles.

- Coram, NY, USA

I have a 2002 Grand Cherokee overland. I realized my heater vents on the passenger side weren't working after the vehicle was beyond the 36,000 mile warranty. I believe the failure was long before 36,000 miles but it was too late for the problem to be covered by the warranty. I took it to a dealer who told me the vent-air door had failed. The cost to repair was quoted at being around $1300. I thought it strange that a failure of this type would occur especially in a vehicle with low mileage. I haven't got the vehicle repaired yet but it is certainly an aggravation in the winter. I talked to two people where I work who own Grand Cherokee and both their Jeep have the same problem. Seems like an unusual coincidence. After checking on the internet it appears a lot of Jeep owners are having the same heater-vent door problems. Sounds like a design problem to me that Jeep owners are paying the price for.

- Dallas, GA, USA

Visibility: Defroster/defogger system:windshield:blower blend doors and recirculation doors no longer function. To my knowledge, this is a design flaw and will affect every 1999-2004 Jeep Grand Cherokee with auto climate control. The dealerships request a ridiculously high price for repairs. Jeep/Chrysler should step up and correct this malfunction in their faulty product.

- Houston, TX, USA

On January 22, 2007, I heard a "cracking" noise under the dash as I started my Jeep in the morning. Later that morning it became apparent that it was not possible to get any heat in the cabin, nor was it possible to defrost the windshield. After trying various settings, all that can be achieved is to blow cold (ambient) air (currently 4F) out of the various vents/defroster. This does very, very little to remove frost from the windshield. Additionally, the heater core has begun failing. This releases additional moisture into the cabin, causing even worse fogging (frosting this time of year). This combination of failures renders the defroster totally ineffective, and requires the dangerous act of wiping or scraping the inside of the window about every 5 minutes under normal winter conditions. I am informed that this condition is caused by the breakage of "mix doors" in the HVAC system, a known defective "weak part" that is currently being replaced (at customer expense) on virtually all 1999-2004 Grand Cherokee with automatic climate controls. Breakage of these parts can constitute a serious hazard, and should be a required recall by DC. I have had to undertake this repair myself - a huge task, as I do not have the $1800 to have the dealer repair it.

- Auburn, NY, USA

It appears that all Jeep from 99-04 have a blend door malfunction. I bought my Jeep used in 2006 it is a 2002 with 62000 mile on it bought it in the summer and it was 100 degrees out. Had no idea that the heater did not function 2 months later the temperature dropped and I was in the cold on the passenger side. Contacted dealer scheduled repair had to pay half of the $840 bill. Was told it would probably do this again, since it is an all to common problem with the dual temp electronic climate zone models. Just thankful no one got hurt if window was unable to defrost and caused an accident.

- Evans , CO, USA

Heater blend door failure, heater constantly blows cool air, vehicle only has 35,000 miles on it dealer estimate to fix $1200-$1500 dollars.

- San Ramon, CA, USA

Heater blend door inoperable. My pregnant wife and I were driving in the mountains near big bear, California. It was about 30 degrees that morning and the heater didn't work. It actually blew cold air on the windshield, and it froze blocking our view when we ran off the road. We could have been killed.

- San Diego, CA, USA